**Core Concept:** The topic being tested in this question is the clinical syndrome called **Keratodontia** or **Hereditary Enamel Deficiency (HED)**. This is a genetic disorder caused by mutations in the **amelogenin** gene, leading to defects in enamel formation and calcification. It affects the development and structure of teeth and keratinized skin, particularly in the hands and feet.

**Why the Correct Answer is Right:** Keratodontia is characterized by the following features:
1. **Hyperkeratosis of hands and feet:** This is the excessive thickening and hardening of the skin on the palms, soles, and fingertips, due to abnormal keratinization.
2. **Severe destruction of periodontal tissues:** The condition results in inflammation, loss of attachment, and resorption of alveolar bone, leading to periodontal destruction.
3. **Calcification of dura:** This refers to calcification of the dura mater, which is the outer layer of the brain and spinal cord meninges. This is a rare complication and not a common feature of Keratodontia.

**Why Each Wrong Option is Incorrect:**
1. Option A: **Hyperkeratosis of hands and feet alone** would not be considered Keratodontia, as the dental manifestations are essential for diagnosis.
2. Option B: **Severe destruction of periodontal tissues alone** would not be Keratodontia, as the primary feature is hyperkeratosis of hands and feet.
3. Option C: **Calcification of dura mater** is a rare feature and not a core characteristic of Keratodontia.
4. Option D: **Hyperkeratosis of hands and feet without severe destruction of periodontal tissues** would not be considered Keratodontia, as the dental manifestations are essential for diagnosis.

**Core Concept:** Keratodontia is a rare genetic disorder affecting the enamel formation and keratinization of skin, hair, and nails. Mutations in the amelogenin gene lead to abnormal enamel calcification, which results in hyperkeratosis and dental abnormalities.

**Clinical Pearl**: The presence of dental manifestations is crucial for the diagnosis of Keratodontia, as it is a rare condition with overlapping features with other disorders like pachyonychia congenita. However, the combination of hyperkeratosis of hands and feet, severe destruction of periodontal tissues, and calcification of dura mater is unique to Keratodontia.